Dezocine[(-)-13.beta.-amino-5,6,7,8,9,10,11,12-octahydro-5.alpha.-methyl-5, 11-methanobenzocyclodecen-3-ol] is an orally and parenterally active analgesic agent possessing a narcotic antagonist activity. As the hydrobromide salt, Dezocine is a pale, cream-colored odorless crystalline powder which is soluble in water at a concentration greater than 20 mg/ml. Initial clinical studies employing this drug at concentrations of 1, 2, 3, 4, and 5 mg/ml. in saline were conducted with lyophilized product reconstituted at the time of administration.